Ultra-high temperature ablation behavior of MoAlB ceramics under an oxyacetylene flame
Ultra-high temperature ablation behavior of MoAlB ceramics under an oxyacetylene flame
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DOI：
10.1016/j.jeurceramsoc.2019.01.016
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发表时间：
2019-06-01
影响因子：
5.7
通讯作者：
Sloof, Willem G.
中科院分区：
文献类型：
--
作者：
Bei, Guoping;van der Zwaag, Sybrand;Sloof, Willem G.
研究了多晶、全致密、主要是单相 MoAlB 陶瓷盘在氧乙炔火焰下的超高温烧蚀。当表面温度达到约2050℃（火焰温度约3000℃）时，线性烧蚀速率从前30秒期间的1.3μm/s下降到60秒后的0.7μm/s。在长达 60 秒的时间内，MoAlB 由于形成了保护性粘性表面 Al2O3 层，因此具有耐烧蚀性。随着烧蚀时间的延长，保护性 Al2O3 鳞片变得多孔，并在 120 秒后在中心烧蚀区域几乎完全被破坏。这加速了大量挥发性物质（主要是硼和钼氧化物）的形成，导致耐烧蚀性降低。
The ultra-high temperature ablation of a polycrystalline, fully dense, predominantly single phase MoAlB ceramic discs under an oxyacetylene flame is examined. The linear ablation rate decreases from 1.3 mu m/s during the first 30 s to - 0.7 mu m/s after 60 s when the surface temperature reached about 2050 degrees C (with a flame temperature around 3000 degrees C). Up to 60 s, the MoAlB is ablation resistant due to the formation of a protective and viscous surface Al2O3 layer. As the ablation time is prolonged, the protective Al2O3 scale becomes porous and is almost fully destroyed at the central ablation region after 120 s. This accelerates the formation of large amounts of volatile species (mainly B and Mo oxides), resulting in a reduction in the ablation resistance.